Case or carton forming or erecting machines exist wherein an operator initially manually expands a flattened carton blank into an open or expanded carton blank such that the open or expanded carton blank comprises two oppositely disposed minor end walls and two oppositely disposed major side walls, and wherein further, a pair of oppositely disposed minor end wall top flaps and a pair of oppositely disposed major side wall top flaps extend vertically upwardly, while a pair of oppositely disposed minor end wall bottom flaps and a pair of oppositely disposed major side wall bottom flaps extend vertically downwardly. Subsequently, the operator inserts the opened or expanded carton blank into the case or carton former or erector, and as the opened or expanded carton blank is lowered into the case or carton forming or erecting machine, switch mechanisms are activated such that when the opened or expanded carton blank is fully inserted into the case or carton forming or erecting machine, a bottom flap folding sequence is initiated whereby, for example, the pair of oppositely disposed minor end wall bottom flaps are first folded upwardly and inwardly, by means of a first pair of oppositely disposed actuators, so as to partially form the bottom wall portion of the case or carton, and subsequently, the pair of oppositely disposed major side wall bottom flaps are folded upwardly and inwardly, by means of a second pair of oppositely disposed actuators, so as to effectively complete the formation of the bottom wall portion of the case or carton.
It is noted, however, that the pair of oppositely disposed folded minor end wall bottom flaps and the pair of oppositely disposed folded major side wall bottom flaps exhibit a predetermined amount of resiliency or memory which tends to want to cause such oppositely disposed minor end wall bottom flaps and such oppositely disposed major side wall bottom flaps to return to their previously opened or expanded states or positions at which the oppositely disposed minor end wall bottom flaps and the oppositely disposed major side wall bottom flaps will once again extend vertically downwardly, as opposed to remaining in their currently folded states or positions at which the pair of oppositely disposed minor end wall bottom flaps and the pair of oppositely disposed major side wall bottom flaps form the bottom wall portion of the case or carton. However, since the oppositely disposed folded minor end wall bottom flaps and the oppositely disposed folded major side wall bottom flaps are disposed in contact with the first and second pairs of oppositely disposed actuators, the oppositely disposed folded minor end wall bottom flaps and the oppositely disposed folded major side wall bottom flaps cannot actually pivot downwardly and outwardly so as to return to their original opened or expanded positions. Accordingly, the resiliency or memory forces inherent within the oppositely disposed folded minor end wall bottom flaps and the oppositely disposed folded major side wall bottom flaps act upon the first and second pairs of oppositely disposed actuators and tend to cause the case or carton to move vertically upwardly against and away from the first and second pairs of oppositely disposed actuators, thereby undoing or reversing the previously achieved folding of the oppositely disposed folded minor end wall bottom flaps and the oppositely disposed folded major side wall bottom flaps, and the consequent formation of the case or carton bottom wall portion, unless the operator manually pushes downwardly upon the case or carton so as to effectively hold the same in contact with the underlying first and second pairs of oppositely disposed actuators. This is not actually practical, however, because once the case or carton has had its oppositely disposed folded minor end wall bottom flaps and its oppositely disposed folded major side wall bottom flaps folded upwardly and inwardly in order to form the bottom wall portion of the case or carton, the case or carton is then ready to be filled with product, and in order to manipulate the product filling apparatus, the operator cannot maintain his downward force upon the case or carton. Therefore, for example, an additional operator is required to perform the filling of the case or carton with the designated product while the original operator maintains the case or carton in its original position upon the underlying first and second pairs of oppositely disposed actuators.
A solution to the aforenoted problem has been previously developed whereby a pair of oppositely disposed engagement rollers are fixedly disposed upon opposite interior side portions of the case or carton forming or erecting machine such that when the opened or expanded case or carton blank is initially inserted into the machine, the exterior surface portions of the oppositely disposed major side walls of the case or carton blank will engage the fixed engagement rollers with a predetermined amount of contact force or friction. Accordingly, it can be readily envisioned that when the oppositely disposed minor end wall bottom flaps and the oppositely disposed major side wall bottom flaps are folded upwardly and inwardly so as to form the bottom wall portion of the case or carton, the aforenoted predetermined contact force or friction, developed or generated between the exterior surface portions of the oppositely disposed major side walls of the case or carton and the fixed engagement rollers, will in fact restrain the case or carton against undergoing any upward or vertical movement so as to maintain the case or carton at its position upon the first and second pairs of oppositely disposed actuators whereby the product filling operation can then commence.
The problem with this system, however, is that the fixedly mounted engagement rollers must be disposed at a predetermined distance from or relative to each other which is less than the width of the opened or expanded case or carton blank such that the aforenoted degree of contact force or friction, developed or generated between the exterior surface portions of the oppositely disposed major side walls of the case or carton and the fixed engagement rollers, will be sufficient so as to in fact be capable of restraining the case or carton against undergoing any upward or vertical movement. This relative disposition of the fixed engagement rollers, however, has rendered the insertion of the opened or expanded case or carton, into the case or carton forming or erecting machine, quite difficult and tedious leading to decreased production and increased operator fatigue.
A need therefore exists in the art for a new and improved case or carton forming or erecting machine which can in fact easily accommodate the insertion of the opened or expanded case or carton blank into the case or carton forming machine, and which can likewise additionally automatically retain the opened or expanded case or carton at its position, at which the oppositely disposed minor end bottom flaps and the oppositely disposed major side bottom flaps have been folded upwardly and inwardly, without any forces being required to be impressed upon the opened or expanded case or carton by operator personnel.